Quantum Nature of the Nanoworld

The particles of matter (electrons, protons, neutrons) provide limits to the smallness of anything composed of chemical matter, which is itself composed of atoms. The rules that these particles obey are different from the rules of macroscopic matter. An understanding of the rules is useful to understand the structure of atoms and chemical matter. An understanding of these rules, and of the relation between the wave and particle natures of light, is also key to understanding deviations from behavior of devices and machines that will appear as their dimensions are reduced toward the atomic size in any process of scaling.

One of the areas in which anticipated failures of classical scaling are of intense interest is in microelectronic devices, where it is obvious that Moore's Law (Figure 1.2), of increasing silicon chip performance, will eventually be modified. For one thing, the new rules allow a particle to penetrate, or tunnel through, a barrier. Such an effect is becoming more likely in the gate oxide of field effect transistors, as scaling efforts reduce its thickness.

The other aspect of the new nanophysical rules is that they permit new device concepts, such as the Esaki tunnel diode, mentioned in Chapter 1.

The new rules say that all matter is made of particles, but that the particles have an associated wave property. That wave property was noted in connection with Figure 3.8, which exhibited electron ripples.

One of the first quantum rules discovered, which had a large impact on understanding of atoms and their absorption and emission of light, was the quantization of angular momentum and energy levels of an electron in a hydrogen atom. This was first discovered in 1913 by Nils Bohr [1], whose work also stimulated further progress until by 1926 or so a more complete understanding of the wave properties of matter was achieved by Schrodinger [2].

4 Quantum Nature of the Nanoworld 4.1

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